package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.config.RedissonConfig;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    //阻塞队列
//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);

    private ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

//    private class  VoucherOrderHandler implements Runnable{
//        @Override
//        public void run(){
//            while(true){
//                //1、获取队列中的订单信息
//                try {
//                    VoucherOrder voucherOrder = orderTasks.take();
//                    //2、创建订单
//                    handleVoucherOrder(voucherOrder);
//                } catch (Exception e) {
//                    log.info("处理订单异常");
//                }
//            }
//        }
//    }

    private class VoucherOrderHandler implements Runnable{
        @Override
        public void run(){
            String queueName = "stream.orders";
            while(true){
                //1、获取队列中的订单信息
                try {
                    //1、获取消息队列中的订单消息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //2、判断消息获取是否成功
                    if (list == null || list.isEmpty()){
                        //2.1、获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    //2.2 获取成功，可以下单
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    //3、ack确认
                    handleVoucherOrder(voucherOrder);
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());

                } catch (Exception e) {
                    //出错的时候，消息可能会丢失，所以必须重新处理此条消息
                    log.info("处理订单异常", e);
                    handlePendingList();
                }
            }
        }
    }

    private void handlePendingList() {
        String queueName = "stream.orders";
        while(true){
            //1、获取队列中的订单信息
            try {
                //1、获取消息队列中的订单消息
                List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1", "c1"),
                        StreamReadOptions.empty().count(1),//.block(Duration.ofSeconds(2)),
                        StreamOffset.create(queueName, ReadOffset.from("0"))
                );
                //2、判断消息获取是否成功
                if (list == null || list.isEmpty()){
                    //2.1、获取失败，说明pending没有消息，结束循环
                    break;
                }
                //2.2 获取成功，可以下单
                MapRecord<String, Object, Object> record = list.get(0);
                Map<Object, Object> value = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                //3、ack确认
                handleVoucherOrder(voucherOrder);
                stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());

            } catch (Exception e) {
                log.info("处理订单异常", e);
            }
        }
    }

    private IVoucherOrderService proxy;

    private void handleVoucherOrder(VoucherOrder voucherOrder) {

        Long userId = voucherOrder.getUserId();
        //创建锁对象
        //Redisson
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();

        if (!isLock){
            log.error("不允许重复下单");
            return;
        }

        try {
            proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }

    @Override
    public Result seckillVoucher(Long voucherId) {

        Long userId = UserHolder.getUser().getId();
        long orderId = redisIdWorker.nextId("order");
        //1、执行lua脚本
        int res = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),
                userId.toString(),
                String.valueOf(orderId)
        ).intValue();

        //2、判断结果是否为0
        if (res != 0){
            //2.1、不为0，代表没有购买资格
            return Result.fail(res == 1? "库存不足" : "不能重复下单");
        }

        //2.2、为0，把下单信息保存到阻塞队列
//        ！！！直接给redis处理了
//        VoucherOrder voucherOrder = new VoucherOrder();
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//
//        orderTasks.add(voucherOrder);

        proxy = (IVoucherOrderService) AopContext.currentProxy();

        //3、返回订单id
        return Result.ok(orderId);
    }

    public Result seckillVoucher_ODDVERSION(Long voucherId) {
        //1、查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);

        //2、判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())){
            return Result.fail("秒杀未开始");
        }

        //3、判断秒杀是否接受
        if (voucher.getEndTime().isBefore(LocalDateTime.now())){
            return Result.fail("秒杀已结束");
        }

        //4、判断库存是否充足
        if (voucher.getStock() < 1){
            return Result.fail("库存不足");
        }

        Long userId = UserHolder.getUser().getId();
//        synchronized (userId.toString().intern()) {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }

        //创建锁对象
//        SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        //获取锁
//        boolean isLock = simpleRedisLock.tryLock(1200);
        //Redisson
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();

        if (!isLock){
            return Result.fail("不允许重复下单");
        }

        try {
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } finally {
            lock.unlock();
        }
    }

    @Transactional
    public  Result createVoucherOrder(Long voucherId){
        //4.5 一人一单
        Long userId = UserHolder.getUser().getId();

        Long count = query()
                .eq("user_id", userId)
                .eq("voucher_id", voucherId)
                .count();

        if (count > 0) {
            return Result.fail("用户已经购买过一次");
        }

        //5、扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherId)//.eq("stock", voucher.getStock())
                .gt("stock", 0)
                .update();

        if (!success) {
            return Result.fail("支付失败");
        }


        //6、创建订单
        VoucherOrder voucherOrder = new VoucherOrder();

        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);

//        Long userId = UserHolder.getUser().getId();
        voucherOrder.setUserId(userId);

        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);

        return Result.ok(voucherOrder);

    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder){
        //4.5 一人一单
//        Long userId = UserHolder.getUser().getId();
        Long userId = voucherOrder.getUserId();


        Long count = query()
                .eq("user_id", userId)
                .eq("voucher_id", voucherOrder.getVoucherId())
                .count();

        if (count > 0) {
            log.info("用户已经购买过一次");
            return ;
        }

        //5、扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId())//.eq("stock", voucher.getStock())
                .gt("stock", 0)
                .update();

        if (!success) {
            log.info("支付失败");
            return ;
        }

        save(voucherOrder);
    }
}
